1. [詞根辨識]
分析repetition和動詞repeat的關系。那么，詞根pet與peat又是什么關系呢？
2. [望文生義]根據(jù)所學詞根的知識推測下列單詞的詞義。
① incompetent a.
② inappetence n.
3. [由此及彼]根據(jù)已知單詞的詞義推斷出其同根詞的詞義。
① competitor n.競爭者→competitress n.
② centrifugal a.離心的→centripetal n.
4. [尋根問底]指出下列單詞的詞根并領會其詞義的由來。
① perpetual a.永存的
② perpetuity n.永存（提示：per-=through）
70. ple(t), plen [L]=to fill;full裝滿（的）
常用詞complement，complete和plenty之間有同根關系。詞根ple來自拉丁動詞plere的不定式詞干，plet是它的過去分詞pletum的詞干，意為to fill（充滿）；plen是同源的拉丁形容詞plenus的詞干部分，意為full（充滿的），因為同源近義，把它們放在一起介紹。
complement [com- = together 一起；ple = to fill 裝滿；-ment n. = the means表手段→“the means of filling together一起填滿的手段”→]Ⅰn. something that completes or makes perfect補充，補充物：Travel is an excellent complement to education.旅行能彌補學識之不足。→Ⅱv. form a complement to補足，補充：Reading and writing complement each other.讀與寫相輔相成。
▽complementary [complement;-ary n.] n.（互為）補充的
supplement [sup-(sub-）=from under自下；ple=to fill裝滿；-ment n.=the act or result表行為或結果→“the act or result of filling from under自下而上裝滿的行為或結果”→]Ⅰn. something added to complete or reinforce填補物，增補物：a supplement to an encyclopedia百科全書的補編→Ⅱv. complete or extend by a supplement增補；補充：He supplements his income by sparetime work.他靠業(yè)余打工補充收入。
▽supplementary [supplement;-ary a.] a.增補的；追加
complete [com-=together一起；plet =to fill裝滿；-e→“to fill together一起裝滿，不留余地的”→]Ⅰa.① having all parts;lacking nothing全部的；完整的：a complete set of Shakespeare's plays整套莎士比亞戲劇集② finished完成的：My homework is complete.我的作業(yè)做完了。→Ⅱv. finish完成：to complete an assignment完成任務
▽completist [complet(e) a.;-ist n.] n.求全主義者
completive [complet(e) v.;-ive a.] a.起完全作用的；完成的
deplete [de-=to undo取消；plet=to fill裝滿；-e→“to undo that of filling取消裝滿的東西”→] v. use up the supply of;decrease badly耗盡；大大減少：The drought depleted our water supply.干旱耗盡了我們的水源。
▽depletion [deplet(e);-ion n.] n.耗盡；枯竭
replete [re-=again再；plet=to fill裝滿；-e→“to fill again and again不斷裝滿的”→] a. fully supplied充滿的，充實的：a speech replete with humor幽默十足的講演
plenty [plen=fill充滿的；-ty n.=the state表狀態(tài)→“the state of being full充滿的狀態(tài)”→] n. full amount;abundance充分；豐富：resources in plenty豐富的資源
▽plentiful [plent(y);-i-;-ful a.] a.豐富的；充足的
replenish [re-=again再；plen=full充滿的；-ish v.=to make使……→] v. make full again;fill again把……再裝滿，再備足：to replenish the refrigerator with food把空冰箱再裝滿食物
▽replenisher [replenish;-er n.] n.補充物；補償物
